1. Field of the Invention
The invention generally relates to a manufacturing method of a plastic product, and more particularly, to a manufacturing method of a glass fiber product and a portable electronic device.
2. Description of Related Art
Along with the development of technologies, the design of electronic products has been going towards light weight and slimness. Presently, the casings of electronic products are usually made of plastic materials. Such materials are inexpensive but cannot be made too thin due to the limitation in their rigidity. Additionally, in a conventional plastic molding process, the mold adopted has a complicated structure, and accordingly it takes a long time to make the mold. Besides, it is time-consuming and inflexible to modify the internal structure of the mold. Due to the complicated mold structure, a product cannot be integrally manufactured by using the mold. Namely, the mold offers a low applicability.
In addition, the conventional plastic injection molding technology is to inject a melted plastic material into a mold at about 40-50° C. and unload the mold after the plastic material cools down. However, if a semi crystalline material is used and cannot be controlled to cool down at above the crystallizing temperature thereof, the problem of nonuniform deformation may be produced in the finished products. Moreover, the conventional plastic injection molding technology achieves the heating effect through water or oil. However, when the manufacturing temperature of the conventional plastic injection molding needs to go over 100° C., the water heating and oil heating occur some problems. For example, the water may exist in liquid and vapor phases (not in pure liquid) in the water pipe at a temperature over 100° C., and the mold will not be under uniform heating. In the oil heating process, oil leakage thru the oil pipe may occur and damage the mold. Thereby, many problems as mentioned in above manufacturing processes need to be resolved.